Malherbe's Canons of French Poetry
(1) Poetry is to contain only such words as are in common use by well-educated Parisians.
(2) A word ending with a vowel must in no case be followed by a word beginning with a vowel.
(3) One line in no wise is to run into another.
(4) The caesura must always be most strictly observed.
(5) Every alternate rhyme must be feminine.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894